Preparation of beta-aminopropionamides



PREPARATION OF -.t9-AMINOPROPIONAMH)ES "Charles H. 'shramm, 'Hills'flale, 'Nl, assigiior to Lever {Brothers Company, New York, N.Y., a corporation of Maine I 'No Drawing. Application November 1, 1952.

Serial No. 318,317 i Claim. (onto-'45s This invention relates to novel ,B-alkylaminopropionamides having the following general formula:

. Iii-AI CHzCHC N R4 3 n "in which "R is selected from the group consisting of "saturated and unsaturated acyclic hydrocarbon radicals having 8 to 18 carbon atoms;-R and R are selected from the group consisting of hydrogen, alkyl having 1 to 12 carbon atoms, alkylol having 1 to 5 carbon atoms, alkylol linked to nitrogen through 1 to Salkylene oxide groups, the alkylene group having 1 to 5 carbon atoms, alkyl sulfate of 1 to 5 carbon atoms, and alkyl sulfonate of 1 to 5 carbon atoms; 11 is an integerirom 1 to 2.; and R is hydrogen when n is 1.

Generally speaking, the novel compounds of this invention may be prepared by reacting a saturated or an unsaturated acyclic amine with an acrylate to form an aminopropionate and reacting the propionate with an amine to form an aminopropionamide. For example, an alkylamine may be reacted with an acrylate to form an alkylamino propionate and the'latter compound is reacted withan amine to form an alkylaminopropionamide as shown by the following sequence 'of reactions:

(1 R,NH CHFOHCOOOH; nlNncmongooooH alkylamine Methyl Methyl-fl-alkylacrylate aminopropionate 2 mnnomontoooorn RzRaNH Methyl-B-alkyl- Amine aminopropionate R1NHCH2CH CON(R2)R onson B-alk'ylaminopronionamide Methyl alcohol which R is selected from the group consisting. of saturated and unsaturated acyclic hydrocarbon radicals having 8 to '18 carbon atoms; R and R are selected from the group consisting of hydrogen, alkyl having 1 to 12 carbon atoms,'alkylol having 1 to 5 carbon atoms, alkylol'linked to nitrogen through'l to 5 alkylene oxide :groups, the alkylene group having 1 to 5 carbon atoms, alkylsulfate of 1 to 5 carbon atoms, and alkyl sulfonate of 1 to 5 carbon atoms.

The above sequence 'of reactions shows the preparation of B alkylaminopropionamides. To prepare the it-alkylaminodipropionamides, the same sequence is employed except-that two mols of methyl acrylate are used to each mol of alkylamine, on-a theoretical basis.

Reaction (1) above is essentially the addition of'an active hydrogen component to an a,fi-unsaturated carbonyl system--a reaction which is similar to a Michael condensation. The reaction is performed by merely mixing the necessary amounts of the component starting materials. Some alkylamino diester is also formed in this reaction. However, the reaction of equimolar quantities of alkylamine and methyl acrylate results in the formation of a product which, without further purification, may be used directly in the ammonolysis reaction (2).

The ammonolysis reaction (2) involves the treatment of the alkyl ester with an amine. Ammonia and'ethanolamine are efiicacious reagents for use in this reaction 2,921,085 Patented Jan. 12, "1960 but any compound containing the NH grouping'may he used also, such as alkylolamines, aminecarboxylic acids, aminesulfonic acids, and the like. The ammonolysis reaction is carried out by mixing the ammonia or amine component with the ester product. The reaction when carried out with aqueous solutions of the amine component is a heterogeneous one and is complete in 'five to seven days at room temperature for the C to C esters with longer time being required forthe C C and tallow amine products. The reaction of the ester condensate with the amine under anhydrous conditions may be greatly accelerated by heating on a steam bath, or in other well-known manner, thus decreasing the time of reaction to about twenty-four hours.

The reaction of decylamine with ethyl acrylate in a mole' ratio of 121 has beenin'vesti'gatedto determine the nature of the products produced'by the reaction. High vacuumnistillation has revealed 'that the mo'nocondensate, "ethyl-,8 decylaminopropionate accounts 'for at least 82% of -the yield. Another 10% of the product was obtained as a forerun which was composed of decylamine,

water and ester. 'The remaining 8% was residue which contained dicondensate. It is known that the aminoesters prepared, according to reaction ('1) above, revert to their compartment starting materials under the influence of heat. Hence, it is not-surprising that decylamine wasobtained in the distillation. A corresponding amount of ethyl acrylate was recovered from the vacuum trap. It is therefore apparent that. the 1:1 condensation product is almost entirely monoester along with some diester. This conclusion is further substantiated bythe fact that'in order to obtain a good yield of the diester, it is necessary to reflux four moles of acrylate to one of amine for 20 hours.

Among the saturated and unsaturated acyclic hydrocarbonamines which may be reacted with methylacrylate according to the method of the invention are dodecylamine, octylamine, decylamine, tetradecylamine, hexadecylamine, octadecylamine, the amines-derived frointhe fattyacids of coconut oil (a mixture of caproic, caprylic, capric, lauric, myristic, palmitic, stearic,-oleic-and linoleic acids), referred to'as coconut amine, and the amines derived from erucic and linolenic acids.

Sulfated derivatives may-be prepared from those compounds in which R and R contain an alkylol group by reacting the propionamide with any of'the well known sulfating agents such as chlorsulf'onic acid, sulfuric acid, oleum, SO -dioxane' complex, and SO -pyridine complex.

Sulfonated derivatives may be prepared fro'rnth'e alkylor alkyleneaminopropionates by reaction with taurine or N-methyl taurine.

The invention will be further-illustrated by reference to the following examples:

of methyl acrylate at a rate sufiiciently "slow'to keep the temperature below 20 C. When all of the acrylate had been added, the reaction mixture was removed from the ice bath and allowed to stand at room temperature for several hours. Although it is possible to distill theester, it was found that the reaction product is of'sufiicient purity for use in the subsequent step.

EXAMPLE 2 ,B-Dodecylaminopropionamide Five hundred cubic centimeters of concentrated aqueous ammonia was added to 240 grams of ethyl B-dodecylaminopr'opionate. The reaction-mixtureg whiclr'was-coru 2,921,085 M I r posed of two liquid layers, was shaken continuously for 16 hours. It was then allowed to stand for an additional two days. At the end of this time the amide had crystallized in the form of shiny white plates, M.P. 75.4- 76.2 C. after recrystallization.

EXAMPLE 3 fl-Dodecylamino-N-(Z-ethylol) -prpi0namide Sixty-one grams of ethanolamine was addedto 271 grams of methyl fi-dodecylaminopropionate. The reaction mixture was shaken occasionally while it was kept at room temperature for six days. At the end of this time, the reaction mixture had turned into a solid cake. A sample of the dodecyl ethanolamide was recrystallized from carbon tetrachloride, ,M.P. 104.2104.8 C.

EXAMPLE 4 Methyl fl-dodecylaminodipropionate To 93 grams of dodecylamine there was added 172 grams of methyl acrylate. This mixture was refluxed for 20 hours after which time the excess acrylate was removed. The yield of crude product was quantitative and the material could be used directly in preparing the diamide. For purposes of identification, a portion of the diester was distilled, B.P. 184-187 C. (0.03 mm.).

EXAMPLE 5 {it-Dodecylaminodipropionamide fl-Octylaminopropionamide Methyl fi-octylaminopropionate was synthesized from 129 grams of octylamine and 86 grams of methyl acrylate, using the same procedure as was used in Example 1. The resulting ester was then reacted with 600 cc. of concentrated aqueous ammonia. The amide crystallized. from the reaction mixture in several days and the melting point of the material after recrystallization from ethyl ether was 58.0-59.0" C. 1

' EXAMPLE 7 ,B-Decylaminopropionamide This compound was prepared according to the procedure of Example 1 from 157 grams of decylamine, 86 grams of methyl acrylate and 550 cc. of concentrated aqueous ammonia. The amide after recrystallization from petroleum ether melted at 66.5-67.5 C.

EXAMPLE 8 fi-Tetradecylaminopropiohizinide Two hundred thirteen grams of'tetradecylamine, 86

grams of methyl acrylate and 500 cc. of ammonia were used in this synthesis following the pr ocedure of Example 1. The amide was recrystallized from ethyl ether and melted at 7677 C.

EXAMPLE 9 fl-Hexadecy laminopropionamitle EXAMPLE 10 fl-Octadecylaminopropionamide I Theoctadecylamide was synthesized from'269 grams of octadecylamine, 86 grams of methyl acrylate and 500 cc. of ammonia following the procedure of Example 1. After recrystallizing from ether, the amide melted at 87 C.

EXAMPLE 11 fi-Octylamino-N-(Z-ethylol) -propionamide Two hundred fifteen grams of methyl fi-octylaminopropionate was synthesized in the same manner as in Example 1. This ester was reacted with 61 grams of ethanolamine at 85-90 C. for twelve hours. Av quantitative yield of the ethanolamide was thus obtained, and the melting point of this compound, after recrystallization from carbon tetrachloride, was 98.098.6 C.

Two hundred and forty-three grams of methyl B-decylaminopropionate made in accordance with Example 1 were reacted with 61 grams of ethanolamine, following the procedure of Example 11, and decyl ethanolamide was obtained. Recrystallization from carbon tetrachloride yielded the pure product melting at 10l.8-

l02.6 C. I

EXAMPLE 13 fi-Tetradecylamino-N-(Z-ethylol) -pr0pi0namide This amide was prepared by reacting 299 grams of methyl S-tetradecylaminopropionate with 61 grams of ethanolamine. After recrystallization from carbon tetrachloride, the ethanolamide melted at l02.4103.4C.'

EXAMPLE 14 V fl-Hexadecylamino-N-(Z-ethylol)-pr0pionamide The reaction of 327 grams of methyl ,B-hexadecylaminopropionate with 61 grams of ethanolamine produced the corresponding ethanolamide which, after recrystallization from carbon tetrachloride melted at 104l05 C.

EXAMPLE 1s v V fl-Cocoamino-di- (N -2 (ethylol -propionamide) amine at room temperature for 21 days.- The reaction mixture was completely homogeneous after 3 days. The

ethanolamide was obtained as a crystalline waxy solid. 1

EXAMPLE 16 ,B-Dodecylamino-di- (N -2 ethylol -propionamide) One hundred eighty-five grams of dodecylamine and 344 grams of methyl acrylate were refluxed for 20 hours. After removing the excess acrylate from the dipropionate ester, 112 grams of ethanolamine were added and the'mixture was reactedat room temperature for 21 days. A homogeneous reaction system resulted when the temperature approached 85 C. The ethanolamide, when recrystallized from acetone, melted at 77.4-79.4 .0.

EXAMPLE 17 v v B-Cocoamino-N- (-2-ethyl0l) -propi0rta niitle Q Two hundred six grams of coconut amine a'nd 86grams of methyl acrylate were reacted at a temperature keptbelow 20 C. by means of an ice bath. When all the acrylate had been added to the amine, the reaction mixture was removed from the ice bath and allowed to stand at room temperature for several hours. This ester was reacted with 61 grams of ethanolamine for 7 days at room temperature. The ethanolamide was obtained as a crystalline waxy solid.

EXAMPLE 18 fl-Cocoamino-N-(polyethyleneoxy) -propionamide Two hundred and ninety-two grams of methyl S-cocoaminopropionate were reacted with 193 grams of a polyethyleneoxide amine of the formula by heating at 3035 C. for 48 hours. The product was obtained as a waxy solid.

EXAMPLE 19 Methyl ,B-cocoaminopropionate EXAMPLE 20 fi-Cocoaminopropionic methyltaurz'de Two hundred and ninety-two grams of methyl fi-cocoaminopropionate were reacted with 161 grams of sodium N-methyltauride by heating at 350 C. for 48 hours. The tauride was obtained as a white crystalline solid.

EXAMPLE 21 B-Cocoamino-N-(Z-ethylol) -propionamide sulfate Sixty-five grams of chlorsulfonic acid was added to 160 grams of fi-cocoamino-N-(2-ethylol)-propionamide dissolved in 300 cc. of carbon tetrachloride. The mixture was kept at 20 C. or below during this addition. The carbon tetrachloride was removed by distillation in vacuo and the residue was neutralized with aqueous sodium hydroxide. The sulfate product after removal of the water was obtained as a yellow semicrystalline solid.

EXAMPLE 22 fi-Cocoamino-N-butylpropionamide Seventy-three grams of n-butylamine were reacted with 292 grams of methyl fl-cocoaminopropionate for 6 days at a temperature of 25 C. The product was obtained as a cream colored crystalline solid.

EXAMPLE 23 Ethylene oxide condensate of B-cocoamino-di-(N-Z-ethylol)-pr0pi0namide Two hundred and eighteen grams of p-cocoamino-di- N-(2-ethylol)-propionamide were reacted with ethylene oxide at a temperature of 50 C. until 132 grams were absorbed. The reaction product after cooling was obtained as a waxy crystalline solid.

EXAMPLE 24 fl-Dodecylamino-N-dodecylpropionamide One hundred and eighty-five grams of dodecylamine was added to 292 grams of methyl-fi-cocoaminopropionate and the reaction mixture was allowed to stand for one week at room temperature after which the dodecylamide was removed by filtration. The amide was obtained as a waxy solid.

EXAMPLE 25 B-OZeylamzno-N- (Z-ethylol) -propionamide The reaction of 267 grams of oleylamine with 86 grams of methylacrylate according to the procedure of Example 1 yielded methyl fi-oleylaminopropionate. This ester was reacted with 61 grams of ethanolamine for 7 days to produce the corresponding ethanolamide in the form of a waxy solid.

The compounds of this invention have utility as surface active agents. For example, the compounds are eflicatious as emulsifying, wetting, foaming and detergent agents. The utility of the compounds of the present invention is further illustrated by the following table showing the values of the surface tension and suds volume measure- It will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention is to be restricted only in accordance with the appended claim.

I claim:

A method for preparing an amide having the structure:

R2 5 in which R; is selected by from the group consisting of saturated and unsaturated acyclic hydrocarbon radicals having from 8 to 18 carbon atoms; and R and R are selected from the group consisting of hydrogen, alkyl having from 1 to 12 carbon atoms, alkylol having from 1 to 5 carbon atoms, alkylol linked to the nitrogen atom through 1 to 5 alkylene oxide groups in which the alkylene group has from 1 to 5 carbon atoms, sulfated alkyl of from 1 to 5 carbon atoms, and sulfonated alkyl of from 1 to 5 carbon atoms, which comprises the steps of reacting an alkylamine having the formula in which R is as defined above, with methylacrylate in the proportion of approximately 1 mol of alkylamine for each 2 mols of methylacrylate and in the presence of a two molar excess of methylacrylate under reflux at a temperature not exceeding the boiling point of methylacrylate for at least 20 hours to form a methylalkylaminodipropionate; and reacting said methyl- -alkylaminodipropionate with an amine having the formula,

in which R and R are selected from the group consisting of hydrogen, alkyl having from 1 to 12 carbon atoms, alkylol having from 1 to 5 carbon atoms, alkylol linked to the nitrogen atom through 1 to 5 alkylene oxide groups in which the alkylene portion has from 1 to 5 carbon atoms, sulfated alkyl radicals of from 1 to 5 carbon atoms, and sulfonated alkyl radicals of from 1 to 5 carbon atoms, to form said amide.

References Cited in the file of this patent UNITED STATES PATENTS 2,139,190 Iselin et a1. Dec. 6, 1938 2,328,021 Katzman et a1. Aug. 31, 1943 2,426,891 Lynch Sept. 2, 1947 2,443,062 Abranovitch June 8, 1948 2,451,436 Erickson Oct. 12, 1948 2,479,525 Thurston Aug. 16, 1949 2,480,439 Bersworth Aug. 30, 1949 2,523,275 Bruce et al. Sept. 26, 1950 OTHER REFERENCES Braun et aL: Ber. Deut. Chem., vol. 60, p. 351 (1927).

UNITED STATES PATENT OFFICE CERTIFICATE ()F CURECTION Patent No. 2,921,085 January 12, 1960 Charles H. Schramm or appears in the printed specification It is hereby certified that err n and that the said Letters of the above numbered patent requiring corre'ctio Patent should read as corrected below.

for "compartment" read component column 5, line 75, for "efficatious" read efficacious column 6., lines 23 to 27 I the formula should appear as shown below instead of as in the patent:

Column 2, line 25,

R '-N- CH2CH2CON\ same column 6, line 28 after "selected" strike out "by",

Signed and sealed this 16th day of August 1960c (SEAL) Attest:

KARL H. AXLINE ROBERT c. WATSON Attesting Officer Commissioner of Patents below instea UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Charles H. Schramm It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

for "compartment" read component column 5, line 75, for "efiicatious" read efficacious column 6 lines 23 to 2'4 the formula should appear as shown d of as in the patent:

Column 2, line 25,

R1-N- CH2CH2CON\ same column 6 line 28, after "selected" strike out "by",

Signed and sealed this 16th day of August 1960,

(SEAL) AtDGSLZ KARL a. AXLINE ROBERT c. WATSON Attesting Officer Commissioner of Patents 

